US10620494B2

US10620494B2 - Electro-optical device and electronic apparatus

Info

Publication number: US10620494B2
Application number: US16/232,771
Authority: US
Inventors: Hiroyuki Oikawa; Toru Nimura; Shinsuke Fujikawa
Original assignee: Seiko Epson Corp
Current assignee: Seiko Epson Corp
Priority date: 2017-12-27
Filing date: 2018-12-26
Publication date: 2020-04-14
Anticipated expiration: 2038-12-26
Also published as: JP6597768B2; US20190196281A1; JP2019117264A

Abstract

In an element substrate of an electro-optical device, a semiconductor layer of a transistor has an L shape bending to overlap with both a scanning line and a data line. A first light shielding layer overlaps with a lower layer side of the semiconductor layer. A first light shielding wall and a second light shielding wall are provided on both sides of a semiconductor layer portion between a channel region and a second source/drain region (drain region) of the semiconductor layer. The first light shielding wall and the second light shielding wall to which a constant potential is applied prevent the semiconductor layer portion from being electrically affected even when the first light shielding wall and the second light shielding wall come close to the semiconductor layer portion.

Description

BACKGROUND

1. Technical Field

The invention relates to an electro-optical device and an electronic apparatus, in which a semiconductor layer of a pixel switching transistor bends in an L shape.

2. Related Art

In an electro-optical device such as a liquid crystal device, an electro-optical layer is provided between an element substrate on which a pixel electrode and a transistor electrode for pixel switching are formed and a counter substrate facing the element substrate, where, for example, light source light incident from the counter substrate is emitted from the element substrate, is modulated pixel by pixel. In regard with the electro-optical device, there has been proposed an aspect in which the semiconductor layer of the transistor bends in an L shape for addressing a reduction in array pitch of the pixels (see JP-A-2012-103385). In JP-A-2012-103385, it is conceivable that a light shielding wall electrically coupled to a gate electrode is provided on both sides of a semiconductor layer portion between a channel region and a source/drain region, to which an electrode is electrically coupled, of the semiconductor layer, and inhibits an occurrence of optical leakage current caused by the light source light being incident on the semiconductor layer portion.

Unfortunately, a scanning signal supplied to the gate electrode may electrically affect the semiconductor layer portion when the light shielding wall electrically coupled to the gate electrode is provided, as in the structure described in JP-A-2012-103385, on both sides of the semiconductor layer portion between the channel region and the source/drain region, to which an electrode is electrically coupled, of the semiconductor layer. Thus, the semiconductor layer portion needs to be sufficiently spaced apart from the light shielding wall. As a result, an aperture region (a region through which light is allowed to pass) of the pixel is narrowed by the light shielding wall, which unfavorably lowers the utilization efficiency of light.

SUMMARY

In view of the above, an object of the invention is to provide an electro-optical device and electronic apparatus capable of suppressing an aperture region of a pixel from being narrowed even when a light shielding wall is provided in a semiconductor layer bending in an L shape.

In order to achieve the above-described object, one aspect of an electro-optical device of the invention includes a first substrate, a pixel electrode provided on one surface side of the first substrate, a scanning line provided in a layer between the first substrate and the pixel electrode, the scanning line extending in a first direction, a data line provided in a layer between the first substrate and the pixel electrode, the data line extending in a second direction intersecting the scanning line, a transistor provided corresponding to an intersection between the scanning line and the data line, the transistor including a semiconductor layer extending in each of the first direction and the second direction, a gate insulating layer, and a gate electrode electrically coupled to the scanning line, a first light shielding layer provided in a layer between the first substrate and the transistor, the first light shielding layer overlapping in a plan view with the semiconductor layer, a first conductive layer provided in a layer between the transistor and the pixel electrode, the first conductive layer being supplied with a constant potential, and a first interlayer insulating film provided in a layer between the first light shielding layer and the first conductive layer. The first light shielding layer is electrically coupled to the first conductive layer via a first contact hole and a second contact hole provided in the first interlayer insulating film in a manner extending along the semiconductor layer, and at least a source/drain region in the semiconductor layer extends between the first contact hole and the second contact hole when viewed from the first direction or the second direction.

In the invention, the semiconductor layer bending in an L shape can ensure an appropriate channel length even when reducing the size of the semiconductor layer in the first direction and in the second direction. This allows addressing a reduction in array pitch of the pixels and the like. The first light shielding layer overlapping with a first substrate side of the semiconductor layer prevents light incident from the first substrate side from entering the semiconductor layer. The source/drain region extending between the first contact hole and the second contact hole can prevent light such as oblique light and diffracted light from entering the source/drain region by a conductive material formed on an inner side of the first contact hole and the second contact hole. This inhibits an occurrence of optical leakage current. It is herein noted that the conductive material formed on the inner side of the first contact hole and the second contact hole, to which a constant potential is applied, prevents the source/drain region from being electrically affected even when the first contact hole and the second contact hole come close to the source/drain region. Accordingly, the first contact hole and the second contact hole can be brought close to the source/drain region, suppressing narrowing of the aperture region of the pixel.

In the invention, an aspect may be employed in which the source/drain region is electrically coupled to the pixel electrode.

In the invention, an aspect may be employed in which a first light shielding wall formed of a light shielding conductive material is provided on an inner wall of the first contact hole, and a second light shielding wall formed of a light shielding conductive material is provided on an inner wall of the second contact hole. According to the above aspect, the first light shielding wall and the second light shielding wall can effectively prevent light such as oblique light and diffracted light from entering the source/drain region. This inhibits an occurrence of optical leakage current in an effective manner.

In the invention, an aspect may be employed in which at least a semiconductor layer portion in the semiconductor layer overlaps with an end portion on a source/drain region side of the gate electrode via a gate insulating layer, the semiconductor layer portion being located between the first light shielding wall and the second light shielding wall. According to the above aspect, light incident from the first substrate side can be effectively prevented from entering the semiconductor layer portion overlapping, via the gate insulating layer, with the end portion of the gate electrode. This inhibits an occurrence of optical leakage current in an effective manner.

In the invention, an aspect may be employed in which the source/drain region includes a first region electrically coupled to the pixel electrode and a second region interposed between a channel region and the first region, the second region having impurity concentration lower than the first region. The second region is entirely located between the first light shielding wall and the second light shielding wall. According to the above aspect, light can be effectively prevented from entering the second region (Lightly-Doped Drain (LDD) region), which effectively inhibits an occurrence of optical leakage current.

In the invention, an aspect may be employed in which the first light shielding wall and the second light shielding wall extend in the first direction along the semiconductor layer. According to the above aspect, light can be effectively prevented from entering the source/drain region, which effectively inhibits an occurrence of optical leakage current.

In the invention, an aspect may be employed in which the first light shielding wall serves as a first plug for filling the first contact hole, and the second light shielding wall serves as a second plug for filling the second contact hole. According to the above aspect, the first light shielding wall and the second light shielding wall can be formed of materials having a high light shielding property regardless of the material or the like constituting the first conductive layer, which enhances light shielding properties of the first light shielding wall and the second light shielding wall.

In the invention, an aspect may be employed in which the first conductive layer has a light shielding property and overlaps in a plan view with the semiconductor layer portion. According to the above aspect, the first conductive layer prevents light from entering the semiconductor layer portion from a pixel electrode side, which effectively inhibits an occurrence of optical leakage current.

In the invention, an aspect may be employed in which the first light shielding layer extends in the first direction to overlap in a plan view with the scanning line. According to the above aspect, light incident from the first substrate side can be prevented from entering the semiconductor layer, which inhibits an occurrence of optical leakage current.

In the invention, an aspect may be employed, which includes a second light shielding layer overlapping in a plan view with the semiconductor layer in a layer between the first light shielding layer and the semiconductor layer, a third contact hole penetrating through a second interlayer insulating film interposed between the second light shielding layer and the gate electrode on an opposite side of the semiconductor layer portion to the source/drain region in a region overlapping in a plan view with the scanning line, and a third light shielding wall formed of a conductive material covering an inner wall of the third contact hole. According to the above aspect, the third light shielding wall prevents light from entering the semiconductor layer portion and the like from a side on which neither the first light shielding wall nor the second light shielding wall is formed. This further inhibits an occurrence of optical leakage current.

In the invention, an aspect may be employed in which the gate electrode includes a first electrode portion overlapping with the semiconductor layer, and a second electrode portion overlapping in a plan view with the scanning line, the second electrode portion protruding from the first electrode portion toward an opposite side to the source/drain region. The third contact hole is provided at a position overlapping in a plan view with the second light shielding layer and the second electrode portion. According to the above aspect, the third contact hole overlapping in a plan view with the scanning line suppresses the aperture region of the pixel from being narrowed regardless of the provision of the third light shielding wall.

In the invention, an aspect may be employed in which the scanning line is provided in a layer between the gate electrode and the pixel electrode. The gate electrode is electrically coupled, on an opposite side of the semiconductor layer portion to the source/drain region, to the scanning line via a fourth contact hole penetrating through a third interlayer insulating film interposed between the gate electrode and the scanning line. According to the above aspect, the scanning line does not impede the first light shielding wall and the second light shielding wall from being formed unlike the case where the scanning line is provided between the first light shielding layer and the semiconductor layer.

In the invention, an aspect may be employed, which includes a second conductive layer provided in a layer between the first conductive layer and the pixel electrode. The second interlayer insulating film is provided with a fifth contact hole penetrating through a fourth interlayer insulating film in the second interlayer insulating film to partially communicate with the first contact hole, the fourth interlayer insulating film being interposed between the first conductive layer and the second conductive layer, and a sixth contact hole penetrating through the fourth interlayer insulating film to partially communicate with the second contact hole. The first light shielding wall is integrally provided from the fifth contact hole to the first contact hole, and the second light shielding wall is integrally provided from the sixth contact hole to the second contact hole. According to the above aspect, a common potential can be supplied to the first conductive layer via the second conductive layer. The first conductive layer can be electrically coupled to the second conductive layer by means of the first light shielding wall and the second light shielding wall.

In the invention, an aspect may be employed in which the second conductive layer includes a first capacitance electrode. Between the first conductive layer and the pixel electrode is provided a second capacitance electrode overlapping in a plan view with the first capacitance electrode via a dielectric layer. The second capacitance electrode is electrically coupled to the pixel electrode. According to the above aspect, a holding capacitor can be configured by the second conductive layer used as the relay electrode for the first conductive layer.

In the invention, an aspect may be employed, including a second substrate facing the first substrate, a common electrode formed on a surface on a first substrate side of the second substrate, and an electro-optical layer provided between the first substrate and the second substrate. The constant electric potential serves as a common electric potential applied to the common electrode. According to the above aspect, in particular, the semiconductor layer portion is prevented from being electrically affected even when the first light shielding wall and the second light shielding wall come close to the semiconductor layer portion. Accordingly, the first light shielding wall and the second light shielding wall can be brought close to the semiconductor layer portion, suppressing narrowing of the aperture region of the pixel.

The display device according to the invention is used for various types of electronic apparatuses. In the invention, when an electro-optical device is used for a projection-type display device among electronic apparatuses, the projection-type display device is provided with a light source unit configured to emit light supplied to an electro-optical device, and a projection optical system configured to project light modulated by the electro-optical device.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.

FIG. 1 is a plan view illustrating an electro-optical device to which the invention is applied.

FIG. 2 is a cross-sectional view illustrating the electro-optical device illustrated in FIG. 1.

FIG. 3 is a block diagram illustrating an electrical configuration of the electro-optical device illustrated in FIG. 1.

FIG. 4 is a plan view illustrating a plurality of pixels adjacent to each other in the electro-optical device illustrated in FIG. 1.

FIG. 5 is an enlarged plan view illustrating one of the pixels illustrated in FIG. 4.

FIG. 6 is a cross-sectional view taken along a line A-A′ of the pixel illustrated in FIGS. 4 and 5.

FIG. 7 is a cross-sectional view taken along a line B-B′ of the pixel illustrated in FIGS. 4 and 5.

FIG. 8 is a cross-sectional view taken along a line C-C′ of the pixel illustrated in FIGS. 4 and 5.

FIG. 9 is a plan view illustrating a first light shielding layer, a first conductive layer, a second conductive layer, and the like illustrated in FIG. 5.

FIG. 10 is a plan view illustrating a second light shielding layer, a gate electrode, a scanning line, and the like illustrated in FIG. 5.

FIG. 11 is a plan view illustrating a holding capacitor and the like illustrated in FIG. 5.

FIG. 12 is a plan view illustrating a data line and the like illustrated in FIG. 5.

FIG. 13 is a plan view illustrating a capacitance line and the like illustrated in FIG. 5.

FIG. 14 is a schematic configuration diagram of a projection-type display device (electronic apparatus) using an electro-optical device to which the invention is applied.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the invention will be described with reference to the drawings. Note that, in the drawings below, to make each layer and each member recognizable in terms of size, the layers and the members are illustrated in different scales. In describing a layer formed on an element substrate in the following description, an upper layer side or a front face side represents an opposite side (a side on which the counter substrate is located) to a side on which a substrate is located, and a lower layer side represents the side on which the substrate is located. In the descriptions below, a side electrically coupled to a data line 6 a is referred to as a source and a side electrically coupled to a pixel electrode 9 a is referred to as a drain in a source/drain of a transistor 30.

Configuration of Electro-Optical Device

FIG. 1 is a plan view illustrating an electro-optical device 100 to which the invention is applied. FIG. 2 is a cross-sectional view illustrating the electro-optical device 100 illustrated in FIG. 1. As illustrated in FIGS. 1 and 2, in the electro-optical device 100, an element substrate 10 and a counter substrate 20 are bonded together by a seal material 107 creating a predefined gap, where the element substrate 10 faces the counter substrate 20. The seal material 107 is provided in a frame-like shape along an outer edge of the counter substrate 20, where an electro-optical layer 80 such as a liquid crystal layer is provided in a region surrounded by the seal material 107 between the element substrate 10 and the counter substrate 20. Accordingly, the electro-optical device 100 is configured as a liquid crystal device. The seal material 107 is a photocurable adhesive, or a photocurable and thermosetting adhesive, and further compounded with a gap material such as a glass fiber and glass beads for setting a distance between the substrates to a predefined value. The element substrate 10 and the counter substrate 20 are both formed in a quadrangular shape, and in a substantially central portion of the electro-optical device 100, a display region 10 a is provided as a rectangular region. In accordance with the above shapes, the seal material 107 is also formed in a substantially quadrangular shape, and a peripheral region 10 b in a quadrangular frame-shape is provided between an inner peripheral edge of the seal material 107 and an outer peripheral edge of the display region 10 a.

The element substrate 10 includes, as a substrate body, a first substrate 19 having translucency such as a quartz substrate or a glass substrate. On one surface 19 s side of the first substrate 19 on a counter substrate 20 side, a data line drive circuit 101 and a plurality of terminals 102 are formed, outside the display region 10 a, along one side of the sides of the element substrate 10, where a scanning line drive circuit 104 is formed along other sides adjacent to the one side. A flexible wiring board (not illustrated) is coupled to the terminal 102, where a variety of potentials and signals are input to the element substrate 10 via the flexible wiring board.

In the display region 10 a on one surface 19 s of the first substrate 19, a plurality of pixel electrodes 9 a having translucency and formed of ITO (Indium Tin Oxide) film or the like, and a transistor for pixel switching (not illustrated in FIG. 2) electrically coupled to each of the plurality of pixel electrodes 9 a are formed in a matrix pattern. A first alignment film 18 is formed on the counter substrate 20 side of the pixel electrode 9 a, where the pixel electrode 9 a is covered with the first alignment film 18.

The counter substrate 20 includes a second substrate 29 having translucency such as a quartz substrate or a glass substrate as a substrate body. A common electrode 21 having translucency and formed of ITO film or the like is formed on the second substrate 29 on one surface 29 s side facing the element substrate 10, where a second alignment film 28 is formed on the element substrate 10 side of the common electrode 21. The common electrode 21 is formed over substantially the entire surface of the second substrate 29 and covered by the second alignment film 28. On one surface 29 s side of the second substrate 29, a light shielding layer 27 having a light shielding property and formed of resin, metal, or a metal compound is formed on the opposite side of the common electrode 21 to the element substrate 10. A protective layer 26 having translucency is formed between the light shielding layer 27 and the common electrode 21. The light shielding layer 27 is formed, for example, as a partition 27 a in a frame-like shape extending along the outer peripheral edge of the display region 10 a. The light shielding layer 27 may be occasionally formed as a light shielding layer 27 b (black matrix) in a region overlapping in a plan view with a region interposed between the pixel electrodes 9 a adjacent to each other. A dummy pixel electrode 9 b formed simultaneously with the pixel electrode 9 a is formed in the dummy pixel region 10 c overlapping in a plan view with the partition 27 a in the peripheral region 10 b of the element substrate 10.

The first alignment film 18 and the second alignment film 28 are inorganic alignment films (vertical alignment films) including obliquely vapor-deposited film of SiO_x(x<2), SiO₂, TiO₂, MgO, Al₂O₃, and the like, where liquid crystal molecules having negative dielectric anisotropy used for the electro-optical layer 8 are tilt-oriented. Hence, the liquid crystal molecules form a predefined angle with respect to the element substrate 10 and the counter substrate 20. In this way, the electro-optical device 100 is configured as a liquid crystal device of a vertical alignment (VA) mode.

On the element substrate 10, inter-substrate conduction electrodes 109 for establishing electrical conduction between the element substrate 10 and the counter substrate 20 are formed in regions overlapping, outside of the seal material 107, with corner portions of the counter substrate 20. An inter-substrate conduction material 109 a containing conductive particles is disposed on the inter-substrate conduction electrode 109, where the common electrode 21 of the counter substrate 20 is electrically coupled to the element substrate 10 side via the inter-substrate conduction material 109 a and the inter-substrate conduction electrode 109. Hence, a common potential is applied to the common electrode 21 from the element substrate 10 side.

In the electro-optical device 100 of the exemplary embodiment, the pixel electrodes 9 a and the common electrode 21 are formed of an ITO film (translucent conductive film), where the electro-optical device 100 is configured as a transmissive liquid crystal device. In such an electro-optical device 100, an image is displayed in a manner that light incident on the electro-optical layer 80 from one of the element substrate 10 and the counter substrate 20 is modulated while being emitted through the other one of the substrates. In the exemplary embodiment, as indicated by the arrow L, an image is displayed in a manner that light incident from the opposite substrate 20 is modulated by the electro-optical layer 80 for each of the pixels while being emitted through the element substrate 10.

Electrical Configuration of Electro-Optical Device 100

FIG. 3 is a block diagram illustrating an electrical configuration of the electro-optical device 100 illustrated in FIG. 1. In FIG. 3, the electro-optical device 100 includes a liquid crystal panel 100 p of VA mode, where in a central region of the display region 10 a of the liquid crystal panel 100 p, a plurality of pixels 100 a are arranged in a matrix pattern. In the electro-optical panel 100 p, in the element substrate 10 described above with reference to FIG. 1, FIG. 2, and the like, a plurality of scanning lines 3 a extending in a first direction X and a plurality of data lines 6 a extending in a second direction Y are formed on the inner side of the display region 10 a, where the plurality of pixels 100 a are formed corresponding to intersections between the plurality of scanning lines 3 a and the plurality of data lines 6 a. The plurality of scanning lines 3 a are electrically coupled to the scanning line drive circuits 104, and the plurality of data lines 6 a are coupled to the data line drive circuit 101. An inspection circuit 105 is electrically coupled to the plurality of data lines 6 a on the opposite side to the data line drive circuit 101 in the second direction Y.

In each of the plurality of pixels 100 a, there are formed a transistor 30 for pixel switching formed of a field effect transistor or the like, and the pixel electrode 9 a electrically coupled to the transistor 30. The data line 6 a is electrically coupled to the source of the transistor 30, the scanning line 3 a is electrically coupled to the gate of the transistor 30, and the pixel electrode 9 a is electrically coupled to the drain of the transistor 30. An image signal is supplied to the data line 6 a, and a scanning signal is supplied to the scanning line 3 a. In the exemplary embodiment, the scanning line drive circuits 104 are configured as scanning line drive circuits 104 s and 104 t on one side X1 and the other side X2 in an X direction with respect to the display region 10 a, where the scanning line drive circuit 104 s on one side X1 in the X direction drives the scanning lines 3 a of odd numbers, and the scanning line drive circuit 104 t on the other side X2 in the X direction drives the scanning lines 3 a of even numbers.

In each of the pixels 100 a, the pixel electrode 9 a, which faces the common electrode 21 of the second substrate 29 described above with reference to FIG. 1 and FIG. 2 with the electro-optical layer 80 interposed in between, configures a liquid crystal capacitor 50 a. A holding capacitor 55 disposed in parallel with the liquid crystal capacitor 50 a is added to each pixel 100 a to prevent fluctuations of the image signal held by the liquid crystal capacitor 50 a. In the exemplary embodiment, capacitance lines 5 a extending across the plurality of pixels 100 a are formed in the first substrate 19 to configure the holding capacitors 55, where a common potential is supplied to the capacitance lines 5 a. In FIG. 3, although one capacitance line 5 a is illustrated extending in the first direction X, the capacitance line 5 a may be extended in the second direction Y, and may also be occasionally extended in both the first direction X and the second direction Y.

Overview Configuration of Pixel 100 a

FIG. 4 is a plan view illustrating the plurality of pixels 100 a adjacent to each other in the electro-optical device 100 illustrated in FIG. 1. FIG. 5 is an enlarged plan view illustrating one of the pixels 100 a illustrated in FIG. 4. FIG. 6 is a cross-sectional view taken along a line A-A′ of the pixel 100 a illustrated in FIGS. 4 and 5, schematically illustrating a cut view illustrating the pixel 100 a along the semiconductor layer 31 a. FIG. 7 is a cross-sectional view taken along a line B-B′ of the pixel 100 a illustrated in FIGS. 4 and 5, schematically illustrating a cut view illustrating the pixel 100 a along a plane passing through a first light shielding wall 431 and a second light shielding wall 432. FIG. 8 is a cross-sectional view taken along a line C-C′ of the pixel 100 a illustrated in FIGS. 4 and 5, schematically illustrating the cut view illustrating the pixel 100 a along the scanning line 3 a. Note that in FIGS. 4 to 13, scales of the width and the thickness of the lines and the like, are made different to make each of the layers easily recognizable. Also note that in FIGS. 4 and 5, and FIGS. 9 to 13 described below, the layers are represented by the following lines. Further note that in FIGS. 4 and 5, and FIGS. 9 to 13 described below, the positions of end portions of layers, the end portions being overlapped in a plan view with each other, are shifted to make the shape and the like of the layer easily recognizable.

First light shielding layer 1 a is indicated by thick chain line.

Second light shielding layer 2 a is indicated by thin and long broken line.

Semiconductor layer

31 a is indicated by thin and short broken line.

Gate electrode

33 a is indicated by thin two-dot chain line.

First conductive layer 4 a is indicated by thick and short broken line.

Scanning line

3 a and

Relay electrodes

3 b and 3 c are indicated by thick solid lines.

Second conductive layer 7 a (First capacitance electrode) and

relay electrodes

7 b and 7 c are indicated by thin solid lines.

Second capacitance electrode

8 a and

relay electrodes

8 b and 8 d are indicated by thin chain lines.

Data line

6 a and

relay electrodes

6 c and 6 d are indicated by thick and long broken lines.

Capacitance line

5 a and relay electrode 5 c are indicated by thick two-dot chain lines.

Pixel electrode

9 a is indicated by thick solid line.

As illustrated in FIGS. 4 and 5, the pixel electrode 9 a is formed in each of the plurality of pixels 100 a on the surface of the element substrate 10 facing the counter substrate 20, where a first light shielding layer 1 a, the scanning line 3 a, the data line 6 a, and the capacitance line 5 a extend along the inter-pixel region between the pixel electrodes 9 a adjacent to each other. The first light shielding layer 1 a and the scanning line 3 a extend in the first direction X in the inter-pixel region. The data line 6 a and the capacitance line 5 a extend in the second direction Y in the inter-pixel region. The transistor 30 is formed corresponding to the intersection between the data line 6 a and the scanning line 3 a. Note that the first light shielding layer 1 a, the scanning line 3 a, the data line 6 a, and the capacitance line 5 a have light shielding properties. Accordingly, the first light shielding layer 1 a, the scanning line 3 a, the data line 6 a, the capacitance line 5 a, and a region formed in the same layer as these lines serve as the light shielding region 11 through which light does not transmit, and the region surrounded by the light shielding region 11 serves as an aperture region 12 through which light transmits.

As illustrated in FIGS. 6 and 7, in the element substrate 10, interlayer insulating films 41 to 49 are sequentially formed on one surface 19 s side of the first substrate 19, where the first light shielding layer 1 a is formed between the first substrate 19 and an interlayer insulating film 41, and a second light shielding layer 2 a, a semiconductor layer 31 a, a gate electrode 33 a, a first conductive layer 4 a, the scanning line 3 a, a second conductive layer 7 a, a second capacitance electrode 8 a, the data line 6 a, and the capacitance line 5 a are formed between two respective stacked layers of the interlayer insulating films 41 to 49. The pixel electrode 9 a and the first alignment film 18 are sequentially formed on the surface of the interlayer insulating film 49 on the opposite side to the first substrate 19. Accordingly, the scanning line 3 a extends in the first direction X between the first substrate 19 and the pixel electrode 9 a, the data line 6 a extends in the second direction Y intersecting the scanning line 3 a between the scanning line 3 a and the pixel electrode 9 a, and the transistor 30 is provided between the first substrate 19 and the data line 6 a, corresponding to the intersection between the scanning line 3 a and the data line 6 a.

Detailed Description of Each Layer

With reference to FIGS. 6, 7 and 8, and with reference to FIGS. 9 to 13 as appropriate, a detailed configuration of the element substrate 10 will be described. FIG. 9 is a plan view illustrating the first light shielding layer 1 a, the first conductive layer 4 a, the second conductive layer 7 a, and the like illustrated in FIG. 5. FIG. 10 is a plan view illustrating the second light shielding layer 2 a, the gate electrode 33 a, the scanning line 3 a, and the like illustrated in FIG. 5. FIG. 11 is a plan view illustrating the holding capacitor 55 and the like illustrated in FIG. 5. FIG. 12 is a plan view illustrating the data line 6 a and the like illustrated in FIG. 5. FIG. 13 is a plan view illustrating the capacitance line 5 a and the like illustrated in FIG. 5. Note that FIGS. 9 to 13 illustrate the contact holes related to the electrical connection of the electrodes and the like illustrated in those drawings, and illustrate the semiconductor layer 31 a for indicating the position to be referenced.

First, as illustrated in FIGS. 5 and 9, in the element substrate 10, the first light shielding layer 1 a linearly extending in the first direction X is formed, between the first substrate 19 and the interlayer insulating film 41 (between the first substrate 19 and the semiconductor layer 31 a), to overlap in a plan view with the scanning line 3 a. The first light shielding layer 1 a is formed of a conductive film such as a metal silicide film, a metal film, and a metal compound film. In the exemplary embodiment, the first light shielding layer 1 a is formed of a light shielding film such as a tungsten silicide (WSi) film, a tungsten film, and a titanium nitride film.

As illustrated in FIGS. 5 and 10, the second light shielding layer 2 a is formed between the interlayer insulating film 41 and an interlayer insulating film 42. The second light shielding layer 2 a includes a first portion 2 a 1 extending in the first direction X to overlap in a plan view with the scanning line 3 a, and a second portion 2 a 2 protruding, to overlap with the data line 6 a, to one side in the second direction Y from an intermediate portion in the extending direction of the first portion 2 a 1.

Between the interlayer insulating film 42 and an interlayer insulating film 43 is formed the transistor 30 for pixel switching. In the exemplary embodiment, the transistor 30 includes the semiconductor layer 31 a formed on the surface of the interlayer insulating film 42 on the opposite side to the first substrate 19, a gate insulating layer 32 overlaid on the pixel electrode 9 a side of the semiconductor layer 31 a, and the gate electrode 33 a overlapping in a plan view with a semiconductor layer 31 aa on the pixel electrode 9 a side of the gate insulating layer 32.

The semiconductor layer 31 aa bends to overlap with both the scanning line 3 a and the data line 6 a and to form an L shape extending in the first direction X and the second direction Y, in which a bending portion overlapping in a plan view with the gate electrode 33 a serves as a channel region 31 g. The gate electrode 33 a includes a first electrode portion 33 a 1 extending in the second direction Y to overlap in a plan view with the semiconductor layer 31 a, where the first electrode portion 33 a 1 overlaps in a plan view with the semiconductor layer 31 a. Accordingly, the semiconductor layer 31 a includes a first source/drain region 31 b extending in the second direction Y to overlap in a plan view with the data line 6 a and electrically coupled to the data line 6 a, a second source/drain region 31 c extending in the first direction X to overlap in a plan view with the scanning line 3 a and electrically coupled to the pixel electrode 9 a, and the channel region 31 g coupling the first source/drain region 31 b to the second source/drain region 31 c.

In the exemplary embodiment, the transistor 30 includes an LDD structure. Accordingly, each of the first source/drain region 31 b and the second source/drain region 31 c includes first regions 31 b 1 and 31 c 1 in which a high concentration impurity is introduced at a position away from the channel region 31 g, and second regions 31 b 2 and 31 c 2 having impurity concentration lower than the first regions 31 b 1 and 31 c 1 between the channel region 31 g and the first regions 31 b 1 and 31 c 1. Thus, the boundary portion between the second source/drain region 31 c and the channel region 31 g in the semiconductor layer 31 a is a semiconductor layer portion 31 c 0 in the semiconductor layer 31 a, which overlaps with the end portion of the gate electrode 33 a on the second source/drain region 31 c side via the gate insulating layer 32.

The semiconductor layer 31 a is formed of a polysilicon film (polycrystalline silicon film) or the like, where the gate insulating layer 32 includes a two-layer structure of a first gate insulating layer formed of a silicon oxide film formed by thermal oxidization of the semiconductor layer 31 a, and a second gate insulating layer formed of a silicon oxide film formed by a low-pressure CVD method or the like. The gate electrode 33 a is formed of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, and a metal compound film. In the exemplary embodiment, the gate electrode 33 a is formed of a conductive polysilicon film. The gate electrode 33 a includes a second electrode portion 33 a 2 protruding from the first electrode portion 33 a 1 toward the opposite side to one side X2 (the second source/drain region 31 c) in the first direction X, where the second electrode portion 33 a 2 overlaps in a plan view with the scanning line 3 a and the second light shielding layer 2 a.

Turning back to FIGS. 5 and 9, the first conductive layer 4 a is formed between the gate electrode 33 a and the pixel electrode 9 a (between the interlayer insulating film 43 and an interlayer insulating film 44). The first conductive layer 4 a is formed of a conductive film such as a metal silicide film, a metal film, and a metal compound film. In the exemplary embodiment, the first conductive layer 4 a is formed of a light shielding film such as a tungsten silicide (WSi) film, a tungsten film, and a titanium nitride film. In the exemplary embodiment, the first conductive layer 4 a includes a main body portion 4 a 1 overlapping in a plan view with the data line 6 a and a protruding portion 4 a 2 protruding from the main body portion 4 a 1 to overlap with the second source/drain region 31 c, overlapping in a plan view with the channel region 31 g and the second region 31 c 2 of the second source/drain region 31 c.

Turning back to FIGS. 5 and 10, the scanning line 3 a is provided between the gate electrode 33 a and the pixel electrode 9 a (between the interlayer insulating film 44 and an interlayer insulating film 45). The gate electrode 33 a is electrically coupled, on the opposite side to the second source/drain region 31 c, to the scanning line 3 a via a fourth contact hole 44 d penetrating through the third interlayer insulating film (the interlayer insulating films 43 and 44) that is interposed between the second electrode portion 33 a 2 of the gate electrode 33 a and the scanning line 3 a. In the exemplary embodiment, the inner space of the fourth contact hole 44 d is filled with a plug 443 formed of a metal film such as tungsten, where the gate electrode 33 a is electrically coupled to the scanning line 3 a via the plug 443. Between the interlayer insulating film 44 and the interlayer insulating film 45 are formed

relay electrodes

3 b and 3 c that are formed simultaneously with the scanning lines 3 a. The relay electrode 3 b is electrically coupled, as a source electrode, to the first region 31 b 1 of the first source/drain region 31 b via a contact hole 44 b penetrating through the interlayer insulating

films

43 and 44. The relay electrode 3 c is electrically coupled, as a drain electrode, to the first region 31 c 1 of the second source/drain region 31 c via a contact hole 44 c penetrating through the interlayer insulating

films

43 and 44. The inner spaces of the contact holes 44 b and 44 c are filled with

plugs

441 and 442 formed of a metal film such as tungsten, where the

relay electrodes

3 b and 3 c are electrically coupled to the first regions 31 b 1 and 31 c 1 via the

plugs

441 and 442, respectively. Accordingly, the surface of the interlayer insulating film 44 is formed, by chemical mechanical polishing (CMP) or the like, to be a plane continuous with the surfaces of the

plugs

441, 442, and 443.

Turning back to FIGS. 5 and 9, the second conductive layer 7 a is provided between the first conductive layer 4 a and the pixel electrode 9 a (between the interlayer insulating film 45 and the interlayer insulating film 46). The second conductive layer 7 a is formed of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, and a metal compound film. In the exemplary embodiment, the second conductive layer 7 a includes, for example, a multilayer structure of Ti (titanium) layer/TiN (titanium nitride) layer/Al (aluminum) layer/TiN (titanium nitride) layer or a multilayer structure of TiN layer/Al layer/TiN layer.

Relay electrodes

7 b and 7 c formed simultaneously with the second conductive layer 7 a are provided between the interlayer insulating film 45 and an interlayer insulating film 46. The

relay electrodes

7 b and 7 c are electrically coupled to the

relay electrodes

3 b and 3 c via contact holes 45 b and 45 c penetrating through the interlayer insulating film 45, respectively. The inner spaces of the contact holes 45 b and 45 c are filled with

plugs

451 and 452 formed of a metal film such as tungsten, where the

relay electrodes

7 b and 7 c are electrically coupled to the

relay electrodes

3 b and 3 c via the

plugs

451 and 452, respectively. Accordingly, the surface of the interlayer insulating film 45 is formed, by chemical mechanical polishing or the like, to be a plane continuous with the surfaces of the

plugs

451 and 452.

As illustrated in FIGS. 5 and 11, the second conductive layer 7 a serves as a first capacitance electrode constituting the second capacitance electrode 8 a and the holding capacitor 55 formed between the second conductive layer 7 a and the pixel electrode 9 a (between the interlayer insulating film 45 and the interlayer insulating film 46). More specifically, a through hole 46 g reaching the second conductive layer 7 a is formed through the interlayer insulating film 46, where a dielectric layer 40 and the second capacitance electrode 8 a formed on the surface of the interlayer insulating film 46 overlap with the second conductive layer 7 a (the first capacitance electrode) at the bottom of the through hole 46 g. The second capacitance electrode 8 a is formed of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, and a metal compound film. In the exemplary embodiment, the second capacitance electrode 8 a includes, for example, a multilayer structure of Ti (titanium) layer/TiN (titanium nitride) layer/Al (aluminum) layer/TiN (titanium nitride) layer or a multilayer structure of TiN layer/Al layer/TiN layer. It is herein noted that the second conductive layer 7 a is electrically coupled to the capacitance line 5 a described below, to which a common potential is applied. On the contrary, the second capacitance electrode 8 a is electrically coupled to the pixel electrode 9 a and the second source/drain region 31 c. Hence, the second capacitance electrode 8 a is electrically coupled to the relay electrode 7 c via a contact hole 46 c penetrating through the interlayer insulating film 46.

Relay electrodes

8 b and 8 d formed simultaneously with the second capacitance electrode 8 a are provided between the interlayer insulating film 45 and the interlayer insulating film 46. The

relay electrodes

8 b and 8 d are electrically coupled to the relay electrode 7 b and the second conductive layer 7 a via contact holes 46 b and 46 d penetrating through the interlayer insulating film 46, respectively. The inner spaces of the contact holes 46 b, 46 c, and 46 d are filled with

plugs

461, 462, and 463 formed of a metal film such as tungsten, respectively, where the second capacitance electrode 8 a and the

relay electrodes

8 b and 8 d are electrically coupled to the

relay electrodes

7 c and 7 b and the second conductive layer 7 a via the

plugs

461, 462, and 463, respectively. Accordingly, the surface of the interlayer insulating film 46 is formed to be a plane continuous with the surfaces of the

plugs

461, 462, and 463.

As illustrated in FIGS. 5 and 12, the data line 6 a extending in the second direction Y is formed between an interlayer insulating film 47 and an interlayer insulating film 48. The data line 6 a is formed of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, and a metal compound film. In the exemplary embodiment, the data line 6 a includes, for example, a multilayer structure of Ti (titanium) layer/TiN (titanium nitride) layer/Al (aluminum) layer/TiN (titanium nitride) layer or a multilayer structure of TiN layer/Al layer/TiN layer. The data line 6 a is electrically coupled to the relay electrode 8 b via a contact hole 47 b formed through the interlayer insulating film 47 that is interposed between the data line 6 a and the relay electrode 8 b.

Between the interlayer insulating film 47 and the interlayer insulating film 48 are formed

relay electrodes

6 c and 6 d that are formed simultaneously with the data line 6 a, where the

relay electrodes

6 c and 6 d are electrically coupled to the second capacitance electrode 8 a and the relay electrode 8 d via contact holes 47 c and 47 d penetrating through the interlayer insulating film 47, respectively. The inner spaces of the contact holes 47 b, 47 c, and 47 d are filled with

plugs

471, 472, and 473 formed of a metal film such as tungsten, respectively, where the data line 6 a and the

relay electrodes

6 c and 6 d are electrically coupled to the relay electrode 8 b, the second capacitance electrode 8 a, and the relay electrode 8 d via the

plugs

471, 472, and 473, respectively. Accordingly, the surface of the interlayer insulating film 47 is formed to be a plane continuous with the surfaces of the

plugs

471, 472, and 473.

Between the interlayer insulating film 48 and the interlayer insulating film 49 is formed the capacitance line 5 a extending in the second direction Y, where a common potential is applied to the capacitance line 5 a. The capacitance line 5 a is formed of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, and a metal compound film. In the exemplary embodiment, the capacitance line 5 a includes, for example, a multilayer structure of Ti (titanium) layer/TiN (titanium nitride) layer/Al (aluminum) layer/TiN (titanium nitride) layer or a multilayer structure of TiN layer/Al layer/TiN layer. The capacitance line 5 a is electrically coupled to the relay electrode 6 d via a contact hole 48 d formed through the interlayer insulating film 48 that is interposed between the capacitance line 5 a and the relay electrode 6 d. Accordingly, the capacitance line 5 a is electrically coupled to the second conductive layer 7 a (first capacitance electrode), and applies a common potential to the second conductive layer 7 a.

Between the interlayer insulating film 48 and the interlayer insulating film 49 is formed a relay electrode 5 c formed simultaneously with the capacitance line 5 a, where each of the relay electrodes 5 c is electrically coupled to the relay electrode 6 c via a contact hole 48 c penetrating through the interlayer insulating film 48. The inner spaces of the contact holes 48 c and 48 d are filled with

plugs

482 and 483 formed of a metal film such as tungsten, where the relay electrode 5 c and the capacitance line 5 a are electrically coupled to the

relay electrodes

6 c and 6 d via the

plugs

482 and 483, respectively. Accordingly, the surface of the interlayer insulating film 48 is formed to be a plane continuous with the surfaces of the

plugs

482 and 483.

On the surface of the interlayer insulating film, the pixel electrode 9 a and the first alignment film 18 are sequentially layered. The pixel electrode 9 a is electrically coupled to the relay electrode 5 c via a contact hole 49 c formed through the interlayer insulating film 49 that is interposed between the pixel electrode 9 a and the relay electrode 5 c. Accordingly, the pixel electrode 9 a is electrically coupled to the second capacitance electrode 8 a and the first region 31 c 1 of the second source/drain region 31 c. The inner space of the contact hole 49 c is filled with a plug 492 formed of a metal film such as tungsten, where the pixel electrode 9 a is electrically coupled to the relay electrode 5 c via the plug 492. Accordingly, the surface of the interlayer insulating film 49 is formed to be a plane continuous with the surface of the plug 492.

Configuration of Light Shielding Wall

As illustrated in FIGS. 5, 7 and 9, in the element substrate 10, the first light shielding layer 1 a is electrically coupled to the first conductive layer 4 a via a first contact hole 43 e and a second contact hole 43 f provided along the semiconductor layer 31 a on the first interlayer insulating film (the interlayer insulating

films

41, 42, and 43) that is interposed between the first light shielding layer 1 a and the first conductive layer 4 a. At least the second source/drain region 31 c in the semiconductor layer 31 a extends, when viewed from the first direction X or the second direction Y, between the first contact hole 43 e and the second contact hole 43 f. In the exemplary embodiment, at least the second source/drain region 31 c in the semiconductor layer 31 a extends, when viewed from the first direction X, between the first contact hole 43 e and the second contact hole 43 f. At least the semiconductor layer portion 31 c 0 in the semiconductor layer 31 a, which overlaps with the end portion on the second source/drain region 31 c side of the gate electrode 33 a via the gate insulating layer 32, is located between the first contact hole 43 e and the second contact hole 43 f.

Accordingly, at a position opposed to the semiconductor layer portion 31 c 0 on the opposite side to the first source/drain region 31 b is formed the first contact hole 43 e penetrating through the first interlayer insulating film (the interlayer insulating

films

41, 42, and 43) that is interposed between the first light shielding layer 1 a and the first conductive layer 4 a, and on the opposite side to the first contact hole 43 e with the semiconductor layer portion 31 c 0 interposed in between is formed the second contact hole 43 f penetrating through the first interlayer insulating film (the interlayer insulating

films

41, 42, and 43).

It is herein noted that a light shielding conductive material is formed on the inner side of the first contact hole 43 e to cover the inner wall of the first contact hole 43 e, where the first light shielding wall 431 is formed of such a conductive material. A light shielding conductive material is also formed on the inner side of the second contact hole 43 f to cover the inner wall of the second contact hole 43 f, where the second light shielding wall 432 is formed of such a conductive material. Accordingly, the first light shielding layer 1 a is electrically coupled to the first conductive layer 4 a via the interior portions of the first contact hole 43 e and the second contact hole 43 f formed on both sides of the semiconductor layer portion 31 c 0. That is, the first light shielding layer 1 a is electrically coupled to the first conductive layer 4 a via the first light shielding wall 431 and the second light shielding wall 432 formed on both sides of the semiconductor layer portion 31 c 0. The first light shielding wall 431 and the second light shielding wall 432 are formed of a conductive film such as a metal silicide film, a metal film, and a metal compound film. In the exemplary embodiment, the first light shielding wall 431 and the second light shielding wall 432 are formed of tungsten. The tungsten is in a state of embedding into the first contact hole 43 e and the second contact hole 43 f. The first light shielding wall 431 and the second light shielding wall 432 serve as the first plug and the second plug each formed of tungsten, respectively.

It is herein noted that the first contact hole 43 e (the first light shielding wall 431) and the second contact hole 43 f (the second light shielding wall 432) extend in the first direction X along the semiconductor layer 31 a, where the second region 31 c 2 of the second source/drain region 31 c is entirely located between the first light shielding wall 431 and the second light shielding wall 432.

In the exemplary embodiment, between the first conductive layer 4 a and the pixel electrode 9 a is formed a fifth contact hole 45 e penetrating through the fourth interlayer insulating film (the interlayer insulating films 44 and 45) to partially communicate with the first contact hole 43 e, where the fourth interlayer insulating film is interposed between the first conductive layer 4 a and the second conductive layer 7 a, and the first light shielding wall 431 is integrally provided from the fifth contact hole 45 e to the first contact hole 43 e. In the fourth interlayer insulating film (the interlayer insulating films 44 and 45) that is interposed between the first conductive layer 4 a and the second conductive layer 7 a, a sixth contact hole 45 f partially communicating with the second contact hole 43 f is formed, where the second light shielding wall 432 is integrally provided from the sixth contact hole 45 f to the second contact hole 43 f. Hence, the first conductive layer 4 a can be electrically coupled to the second conductive layer 7 a by means of the first light shielding wall 431 and the second light shielding wall 432, where a common potential can be applied to the first light shielding wall 431 and the second light shielding wall 432.

In the exemplary embodiment, between the first light shielding layer 1 a and the semiconductor layer 31 a is formed the second light shielding layer 2 a overlapping in a plan view with the semiconductor layer 31 a, where a third contact hole 42 d penetrating through the interlayer insulating film 42 (the second interlayer insulating film) is formed on the opposite side of the semiconductor layer portion 31 c 0 to the second source/drain region 31 c in the region overlapping in a plan view with the scanning line 3 a and the gate insulating layer 32 that are interposed between the second light shielding layer 2 a and the second electrode portion 33 a 2 of the gate electrode 33 a. A third light shielding wall 421 is provided by the conductive material formed to cover the inner wall of the third contact hole 42 d. Accordingly, the third light shielding wall 421 is electrically coupled to the gate electrode 33 a. In the exemplary embodiment, the third light shielding wall 421 is a portion formed on the inner side of the third contact hole 42 d in the second electrode portion 33 a 2 of the gate electrode 33 a.

Main Effects of the Exemplary Embodiment

As described above, in the electro-optical device 100 of the exemplary embodiment, the semiconductor layer 31 a of the transistor 30, which bends to overlap with both the scanning line 3 a and the data line 6 a, has an L shape extending in the first direction X and in the second direction Y. A sufficient length of the semiconductor layer 31 a can be ensured even when reducing the size of the semiconductor layer 31 a in the first direction X and in the second direction Y, thereby maintaining an appropriate channel length. This allows addressing a reduction in array pitch and the like of the pixels 100 a.

The first light shielding layer 1 a overlaps with the first substrate 19 side of the semiconductor layer 31 a. In particular, in the exemplary embodiment, the first light shielding layer 1 a extends in the first direction X to overlap in a plan view with the scanning line 3 a. Accordingly, light emitted from the first substrate 19 side and reflected to be incident on the first substrate 19 again can be prevented from entering the semiconductor layer 31 a. This inhibits an occurrence of optical leakage current.

The first contact hole 43 e and the second contact hole 43 f provided on both sides of the semiconductor layer portion 31 c 0 between the channel region 31 g and the second source/drain region 31 c of the semiconductor layer 31 a can also prevent light such as oblique light and diffracted light from entering the semiconductor layer portion 31 c 0. This inhibits an occurrence of optical leakage current. Moreover, the first light shielding wall 431 and the second light shielding wall 432 provided in the first contact hole 43 e and the second contact hole 43 f more effectively prevent light such as oblique light or diffracted light from entering the semiconductor layer portion 31 c 0. This inhibits an occurrence of optical leakage current in a more effective manner. It is herein noted that a constant potential is applied to the conductive material (the first light shielding wall 431 and the second light shielding wall 432) formed on the inner side of the first contact hole 43 e and the second contact hole 43 f. In particular, in the exemplary embodiment, a common potential is applied to the first light shielding wall 431 and the second light shielding wall 432. This prevents, even when the first light shielding wall 431 and the second light shielding wall 432 come close to the semiconductor layer portion 31 c 0, the first light shielding wall 431 and the second light shielding wall 432 from electrically affecting the semiconductor layer portion 31 c 0. Accordingly, the first light shielding wall 431 and the second light shielding wall 432 can be brought close to the semiconductor layer portion 31 c 0, preventing the first light shielding wall 431 and the second light shielding wall 432 from bulging too much. Thus, the formation of the first light shielding wall 431 and the second light shielding wall 432 can suppress the aperture region 12 of the pixel 100 a from being narrowed.

The first light shielding wall 431 and the second light shielding wall 432 each extend in the first direction X along the semiconductor layer 31 a, where the second region 31 c 2 (LDD region) of the second source/drain region 31 c is entirely located between the first light shielding wall 431 and the second light shielding wall 432. This prevents light from entering the second region 31 c 2, which further inhibits an occurrence of optical leakage current. Each of the first light shielding wall 431 and the second light shielding wall 432 serves as a first plug for filling the first contact hole 43 e, where the second light shielding wall 432 serves as a second plug for filling the second contact hole 43 f. This allows the first light shielding wall 431 and the second light shielding wall 432 to be formed of materials having high light shielding properties regardless of the material and the like constituting the first conductive layer, which enhances light shielding properties of the first light shielding wall 431 and the second light shielding wall 432.

The first conductive layer 4 a having a light shielding property prevents light from entering the semiconductor layer portion 31 c 0 from the pixel electrode 9 a side. This further inhibits an occurrence of optical leakage current. The third light shielding wall 421 (the third contact hole 42 d) is provided on the opposite side of the semiconductor layer portion 31 c 0 to the second source/drain region 31 c. This allows the third light shielding wall 421 to prevent light from entering the semiconductor layer portion 31 c 0 and the like from a side on which neither the first light shielding wall 431 nor the second light shielding wall 432 is formed. This further inhibits an occurrence of optical leakage current. The third light shielding wall 421 (the third contact hole 42 d) is provided at a position overlapping in a plan view with the second electrode portion 33 a 2 protruding, in the gate electrode 33 a, toward the opposite side to the second source/drain region 31 c. The third light shielding wall 421 overlapping in a plan view with the scanning line 3 a suppresses the aperture region 12 of the pixel 100 a from being narrowed regardless of the provision of the third light shielding wall 421.

The scanning line 3 a provided between the gate electrode 33 a and the pixel electrode 9 a does not impede the first light shielding wall 431 and the second light shielding wall 432 from being formed unlike the case where the scanning line 3 a is provided between the first light shielding layer 1 a and the semiconductor layer 31 a.

Other Exemplary Embodiments

In the above exemplary embodiment, although a plug is used for connecting the relay electrodes, an aspect may be employed, in which the electrode on the upper layer side is partially in contact with the electrode on the lower layer side at the bottom portion of the contact hole. In the above exemplary embodiment, although description is given in which the transistor 30 has the LDD structure, the invention may also be applied in the case of an offset gate structure in which the first source/drain region 31 b and the second source/drain region 31 c are located apart from the end portion of the gate electrode 33 a. In the above exemplary embodiment, although description is given in which light source light is incident from the counter substrate 20, the invention may also be applied in the case where the light source light is incident from the element substrate 10. In the above exemplary embodiment, although the invention is applied to the transmissive electro-optical device 100, the invention may also be applied to a reflective electro-optical device.

Installation Example to Electronic Apparatus

FIG. 14 is a schematic configuration diagram of a projection-type display device (electronic apparatus) using the electro-optical device 100 to which the invention is applied. Note that in the descriptions below, although a plurality of optical modulators 200 (R), (G), and (B) are used to which light in mutually different wavelength regions are supplied, the electro-optical device 100 to which the invention is applied is used in any of the optical modulators 200 (R), (G), and (B). A projection-type display device 210 illustrated in FIG. 14 serves as a projection-type projector configured to project an image on a screen 211 provided anteriorly. The projection-type display device 210 includes a light source 212,

dichroic mirrors

213 and 214, optical modulators 200 (R), (G), and (B), a projection optical system 218, a cross dichroic prism 219, and a relay system 220. Each of the optical modulators 200 (R), (G), and (B), which is the optical modulator 200 described with reference to FIG. 2 and the like, includes, along the traveling direction of the light L, a first polarizing element 241, an optical compensation element 250, the electro-optical device 100, and a second deflection element 242.

The light source 212 is configured by an extra-high-pressure mercury lamp for supplying light including red light, green light, and blue light, for example. The dichroic mirror 213 is configured to be transmissive of red light LR from the light source 212 and reflective of green light LG and blue light LB. The dichroic mirror 214 is configured to be transmissive of blue light LB and reflective of green light LG in the green light LG and the blue light LB reflected by the dichroic mirror 213. In this way, the

dichroic mirrors

213 and 214 constitute a color separation optical system configured to separate light emitted from the light source 212 into red light LR, green light LG, and blue light LB. An integrator 221 and a polarization conversion element 222 are sequentially arranged, between the dichroic mirror 213 and the light source 212, from the light source 212. The integrator 221 equalizes the illuminance distribution of the light irradiated from the light source 212. The polarization conversion element 222 converts the light from the light source 212 into polarized light having a specific vibration direction such as s-polarized light.

The optical modulator 200 (R) modulates the red light LR transmitted through the dichroic mirror 213 and reflected by a reflection mirror 223 in accordance with image signals. The red light LR incident on the optical modulator 200 (R) and then transmitted through the first polarizing element 241 is converted into, for example, s-polarized light. The liquid crystal panel 100 p converts, by modulation in accordance with image signals, the incident s-polarized light into p-polarized light (circularly polarized light or elliptically polarized light in the case of halftone). Moreover, the second deflecting element 242 blocks s-polarized light and transmits p-polarized light. Accordingly, the optical modulator 200 (R) modulates the red light LR in accordance with image signals and then emits the modulated red light LR toward the cross dichroic prism 219.

The optical modulator 200 (G) modulates, in accordance with image signals, the green light LG reflected by the dichroic mirror 213 and then reflected by the dichroic mirror 214. The optical modulator 200 (G) emits the modulated green light LG toward the cross dichroic prism 219.

The optical modulator 200 (B) modulates, in accordance with image signals, the blue light LB reflected by the dichroic mirror 213, transmitted through the dichroic mirror 214, and then passed through the relay system 220. The optical modulator 200 (B) emits the modulated blue light LB toward the cross dichroic prism 219.

The relay system 220 includes

relay lenses

224 a and 224 b and reflection mirrors 225 a and 225 b. The

relay lenses

224 a and 224 b are provided to prevent the loss of light due to the long optical path of the blue light LB. The relay lens 224 a is disposed between the dichroic mirror 214 and the reflection mirror 225 a.

The relay lens 224 b is disposed between the reflection mirrors 225 a and 225 b. The reflection mirror 225 a is disposed to reflect, toward the relay lens 224 b, the blue light LB transmitted through the dichroic mirror 214 and then emitted from the relay lens 224 a. The reflection mirror 225 b is disposed to reflect the blue light LB emitted from the relay lens 224 b toward the optical modulator 200 (B).

The cross dichroic prism 219 serves as a color combining optical system in which two dichroic films 219 a and 219 b are orthogonally arranged in an X shape. The dichroic film 219 a reflects the blue light LB and transmits the green light LG. The dichroic film 219 b reflects the red light LR and transmits the green light LG.

Accordingly, the cross dichroic prism 219 is configured to synthesize the red light LR, the green light LG, and the blue light LB modulated by the optical modulators 200 (R), (G), and (B) respectively and to emit the synthesized light toward the projection optical system 218. The projection optical system 218, which includes a projection lens (not illustrated), is configured to project the light synthesized by the cross dichroic prism 219 onto the screen 211.

Note that such a configuration may also be employed where a λ/2 phase difference compensation element is provided for the optical modulators 200 (R) and (B) for red and blue light, in which the light incident on the cross dichroic prism 219 from the optical modulators 200 (R) and (B) is modulated into s-polarized light, and where the optical modulator 200 (G) is configured without a λ/2 phase difference compensation element, in which the light incident on the cross dichroic prism 219 from the optical modulator 200 (G) is modulated into p-polarized light.

A color synthesizing optical system can be configured to be optimized in view of the reflection characteristics of the dichroic films 219 a and 219 b by modulating the light incident on the cross dichroic prism 219 into different types of polarized light. The red light LR and the blue light LB reflected by the dichroic films 219 a and 219 b as described above may be modulated into s-polarized light, and the green light LG that transmits the dichroic films 219 a and 219 b may be modulated into p-polarized light, taking advantage of the dichroic films 219 a and 219 b normally having excellent reflection characteristics for s-polarized light.

Other Projection-Type Display Devices

In the projection-type display device, an LED light source, a laser light source, or the like for emitting light of each color may be used as the light source unit, and each of the colored lights emitted from the light source may be supplied to a separate liquid crystal device.

The electro-optical device 100 to which the invention is applied may be used for a variety of electronic apparatuses such as a projection-type head-up display (HUD) and a direct viewing-type head-mounted display (HMD) in addition to the above electronic apparatuses. The electro-optical device 100 to which the invention is applied may also be used for electronic apparatuses such as a personal computer, a digital still camera, a liquid crystal television, and the like.

The entire disclosure of Japanese Patent Application No. 2017-250706, filed Dec. 27, 2017 is expressly incorporated by reference herein.

Claims

What is claimed is:

1. An electro-optical device comprising:

a first substrate;

a pixel electrode provided on one surface side of the first substrate;

a scanning line provided in a layer between the first substrate and the pixel electrode, the scanning line extending in a first direction;

a data line provided in a layer between the first substrate and the pixel electrode, the data line extending in a second direction intersecting the scanning line;

a transistor including a semiconductor layer extending in each of the first direction and the second direction;

a first light shielding layer provided in a layer between the first substrate and the transistor, the first light shielding layer overlapping in a plan view with the semiconductor layer;

a first conductive layer provided in a layer between the transistor and the pixel electrode, the first conductive layer being supplied with a constant potential; and

a first interlayer insulating film provided in a layer between the first light shielding layer and the first conductive layer, wherein

the first light shielding layer is electrically coupled to the first conductive layer via a first contact hole and a second contact hole provided in the first interlayer insulating film in a manner extending along the semiconductor layer,

at least a source/drain region in the semiconductor layer extends in a plan view between the first contact hole and the second contact hole,

a first light shielding wall formed of a light shielding conductive material is provided on an inner wall of the first contact hole,

a second light shielding wall formed of a light shielding conductive material is provided on an inner wall of the second contact hole, and

at least a semiconductor layer portion in the semiconductor layer overlaps with an end portion on a source/drain region side of a gate electrode of the transistor via a gate insulating layer, the semiconductor layer onion being located between the first light shielding wall and the second light shielding wall,

the electro-optical device further comprising:

a second light shielding layer overlapping in a plan view with the semiconductor layer in a layer between the first light shielding layer and the semiconductor layer,

a third contact hole penetrating through a second interlayer insulating film interposed between the second light shielding layer and the gate electrode on an opposite side of the semiconductor layer portion to the source/drain region in a region overlapping in a plan view with the scanning line, and

a third light shielding wall formed of a conductive material covering an inner wall of the third contact hole.

2. The electro-optical device according to claim 1, wherein the source/drain region is electrically coupled to the pixel electrode.

3. The electro-optical device according to claim 1, wherein

the source/drain region includes

a first region electrically coupled to the pixel electrode, and

a second region interposed between a channel region and the first region, the second region having impurity concentration lower than that of the first region, and

the second region is entirely located between the first light shielding wall and the second light shielding wall.

4. The electro-optical device according to claim 1, wherein the first light shielding wall and the second light shielding wall extend in the first direction along the semiconductor layer.

5. The electro-optical device according to claim 1, wherein

the first light shielding wall serves as a first plug for filling the first contact hole, and

the second light shielding wall serves as a second plug for filling the second contact hole.

6. The electro-optical device according to claim 1, wherein the first conductive layer has a light shielding property, and overlaps in a plan view with the semiconductor layer portion.

7. The electro-optical device according to claim 1, wherein the first light shielding layer extends in the first direction to overlap in a plan view with the scanning line.

8. The electro-optical device according to claim 1, wherein

the gate electrode includes

a first electrode portion overlapping with the semiconductor layer, and

a second electrode portion overlapping in a plan view with the scanning line, the second electrode portion protruding from the first electrode portion toward an opposite side to the source/drain region, and

the third contact hole is provided at a position overlapping in a plan view with the second light shielding layer and the second electrode portion.

9. The electro-optical device according to claim 1, wherein

the scanning line is provided in a layer between the gate electrode and the pixel electrode, and

the gate electrode is electrically coupled, on an opposite side of the semiconductor layer portion to the source/drain region, to the scanning line via a fourth contact hole penetrating through a third interlayer insulating film interposed between the gate electrode and the scanning line.

10. The electro-optical device according to claim 1, including a second conductive layer provided in a layer between the first conductive layer and the pixel electrode, wherein

the second interlayer insulating film is provided with

a fifth contact hole penetrating through a fourth interlayer insulating film in the second interlayer insulating film to partially communicate with the first contact hole, the fourth interlayer insulating film being interposed between the first conductive layer and the second conductive layer, and

a sixth contact hole penetrating through the fourth interlayer insulating film to partially communicate with the second contact hole, and

the first light shielding wall is integrally provided from the fifth contact hole to the first contact hole, and

the second light shielding wall is integrally provided from the sixth contact hole to the second contact hole.

11. The electro-optical device according to claim 10, wherein

the second conductive layer includes a first capacitance electrode,

between the first conductive layer and the pixel electrode is provided a second capacitance electrode overlapping in a plan view with the first capacitance electrode via a dielectric layer, and the second capacitance electrode is electrically coupled to the pixel electrode.

12. The electro-optical device according to claim 1, including

a second substrate facing the first substrate;

a common electrode formed on a surface on a first substrate side of the second substrate; and

an electro-optical layer provided between the first substrate and the second substrate, wherein

the electric potential serves as a common electric potential applied to the common electrode.

13. An electronic apparatus comprising the electro-optical device according to claim 1.

14. An electro-optical device comprising:

a first substrate;

a pixel electrode provided on one surface side of the first substrate;

at least a source/drain region in the semiconductor layer extends in a plan view between the first contact hole and the second contact hole, a first light shielding wall formed of a light shielding conductive material is provided on an inner wall of the first contact hole,

at least a semiconductor layer portion in the semiconductor layer overlaps with an end portion on a source/drain region side of a gate electrode of the transistor via a gate insulating layer, the semiconductor layer portion being located between the first light shielding wall and the second light shielding wall,

the electro-optical device further comprising:

a second conductive layer provided in a layer between the first conductive layer and the pixel electrode, wherein

the second interlayer insulating film is provided with